1. Field of the Invention
The invention relates to a hot compacting device for use during the production of parts requiring simultaneous pressure and temperature rises, such as thermosetting or thermoplastic material parts.
2. Description of the Prior Art
The invention is advantageously applicable to the production of composite material parts incorporating a conventional organic resin matrix (phenolic or epoxy resin) or a thermoplastic resin matrix. However, the invention is not limited to this application and instead allows the production by molding of any parts simultaneously requiring a pressure and temperature rise.
Composite material parts are generally produced by molding from a blank of the part. During molding, it is necessary to apply to the blank a pressure permitting its shaping and to heat this blank in accordance with a predetermined temperature cycle, so as to permit compacting and, in certain cases, polymerization.
Most frequently, said molding operation is performed in the autoclave, which makes it possible to produce relatively large parts. For producing smaller parts, sometimes molding takes place under a press.
The evolution of the materials used in matrixes of composite materials has made it ever more frequently necessary to increase the pressure applied to the blank of the part during molding. Thus, certain thermoplastic resins must be compacted under a pressure of 50 bars and the compacting pressure of a metal matrix can be equal to or higher than 200 bars.
Under these conditions, the use of an autoclave for carrying out molding is rendered virtually impossible for safety reasons, particularly when producing large parts. Thus, an autoclave e.g. having a useful volume of approximately 1000 m.sup.3, when pressurized to 50 or 20 bars constitutes a considerable hazard for the environment.
Moreover, although it is theoretically possible to carry out press molding under such pressures, this method must be abandoned when the dimensions of the parts increase, due to the overall dimensions and the considerable costs involved for the parts external of the molding equipment and making it possible to apply the pressure.